Hi Ingo, FYI, the error/warning still remains. tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git sched/headers head: 4c707c1c0de83967079b4e385012fa5b00e2cd11 commit: 2343c4a8035421263b16ea777e945cc1b0cbd22f [1471/2384] headers/deps: rcu/wait: Remove <linux/sched/task_flags.h> from <linux/rcuwait.h> config: i386-randconfig-a002-20220124 (https://download.01.org/0day-ci/archive/20220125/202201250610.CvFrmXWz-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git/commit/?id=... git remote add mingo-tip git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git git fetch --no-tags mingo-tip sched/headers git checkout 2343c4a8035421263b16ea777e945cc1b0cbd22f # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from include/linux/mm_types.h:16, from include/asm-generic/fixmap.h:19, from arch/x86/include/asm/fixmap.h:192, from arch/x86/include/asm/apic.h:13, from arch/x86/kernel/apic/hw_nmi.c:15: include/linux/rcuwait.h: In function 'rcuwait_active': 380 | typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ | ^ include/linux/rcupdate.h:490:31: note: in expansion of macro '__rcu_access_pointer' 490 | #define rcu_access_pointer(p) __rcu_access_pointer((p), __rcu) | ^~~~~~~~~~~~~~~~~~~~ include/linux/rcuwait.h:33:11: note: in expansion of macro 'rcu_access_pointer' 33 | return !!rcu_access_pointer(w->task); | ^~~~~~~~~~~~~~~~~~ -- In file included from include/linux/workqueue.h:16, from include/linux/workqueue_api.h:2, from arch/x86/kvm/lapic.c:19: include/linux/rcuwait.h: In function 'rcuwait_active': 380 | typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ | ^ include/linux/rcupdate.h:490:31: note: in expansion of macro '__rcu_access_pointer' 490 | #define rcu_access_pointer(p) __rcu_access_pointer((p), __rcu) | ^~~~~~~~~~~~~~~~~~~~ include/linux/rcuwait.h:33:11: note: in expansion of macro 'rcu_access_pointer' 33 | return !!rcu_access_pointer(w->task); | ^~~~~~~~~~~~~~~~~~ In file included from include/linux/rcuwait_api.h:1, from arch/x86/kvm/lapic.c:20: include/linux/rcuwait.h:34:1: error: control reaches end of non-void function [-Werror=return-type] 34 | } | ^ cc1: some warnings being treated as errors vim +380 include/linux/rcupdate.h 76c8eaafe4f061 Paul E. McKenney 2021-04-21 377 ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 378 #define __rcu_access_pointer(p, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 379 ({ \ 7d0ae8086b8283 Paul E. McKenney 2015-03-03 @380 typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 381) rcu_check_sparse(p, space); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 382 ((typeof(*p) __force __kernel *)(_________p1)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 383 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 384 #define __rcu_dereference_check(p, c, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 385 ({ \ ac59853c06993a Pranith Kumar 2014-11-13 386 /* Dependency order vs. p above. */ \ 506458efaf153c Will Deacon 2017-10-24 387 typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 388 RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 389) rcu_check_sparse(p, space); \ ac59853c06993a Pranith Kumar 2014-11-13 390 ((typeof(*p) __force __kernel *)(________p1)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 391 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 392 #define __rcu_dereference_protected(p, c, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 393 ({ \ f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 394 RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 395) rcu_check_sparse(p, space); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 396 ((typeof(*p) __force __kernel *)(p)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 397 }) 995f1405610bd8 Paul E. McKenney 2016-07-01 398 #define rcu_dereference_raw(p) \ 995f1405610bd8 Paul E. McKenney 2016-07-01 399 ({ \ 995f1405610bd8 Paul E. McKenney 2016-07-01 400 /* Dependency order vs. p above. */ \ 506458efaf153c Will Deacon 2017-10-24 401 typeof(p) ________p1 = READ_ONCE(p); \ 995f1405610bd8 Paul E. McKenney 2016-07-01 402 ((typeof(*p) __force __kernel *)(________p1)); \ 995f1405610bd8 Paul E. McKenney 2016-07-01 403 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 404 :::::: The code at line 380 was first introduced by commit :::::: 7d0ae8086b828311250c6afdf800b568ac9bd693 rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() :::::: TO: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com&gt; :::::: CC: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org